Cubic perovskite structure has been found to play an important role for the nano-rod formation in REBa2Cu3O7-δ films. BaWO4,with a sheelite structure, and BaNb2O6, with a tungsten bronze structure, were doped into REBa2Cu3O7-δ targets. Laser-deposited, these materials formnano-rods in REBa2Cu3O7-δ films accompanied by Ln elements, resulting in the composition of a pseudo-cubic perovskite structure. This was confirmed by selected area electron diffraction patterns (SADP) and composition mapping using energy-dispersive X-ray spectroscopy scanning transmission electron microscope (EDS-STEM) analysis. BaWO4 with a sheelite structure, and BaNb2O6 with a tungsten bronze structure, doped into targets no longer retain their structures, but canform pseudo-cubic perovskite structures in laser-deposited REBa2Cu3O7-δ films. The perovskite crystal structure is thought to beimportant for nano-rod formation in the laser deposited REBa2Cu3O7-δ film.
